Mumps virus, together with parainfluenza types 1 through 4, respiratory syncytial virus, and measles virus are classified in the family Paramyxovirdae. Mumps is an acute infection that causes the painful enlargement of the salivary glands in approximately 70% to 90% of children (4-15 years of age) who develop clinical disease.(2) In 5% to 20% of postpubertal individuals, testicular pain (orchitis in males) and abdominal pain (oophoritis in females) can occur. Other complications include pancreatitis (<5% of cases) and central nervous system disease (meningitis/encephalitis) that occur rarely (about 1 in 6,000 cases of mumps). Widespread routine immunization of infants with attenuated mumps virus has changed the epidemiology of this virus infection. Since 1989, there has been a steady decline in reported mumps cases, with and average of 265 cases each year since 2001. However, a recent outbreak of mumps in 2006 reemphasized that this virus continued to persist in the population, and laboratory testing may be needed in clinically compatible situations.

The laboratory diagnosis of mumps is typically accomplished by detection of antibody to mumps virus. However, due to the limitations of serology (eg, inadequate sensitivity and specificity), additional laboratory testing including virus isolation or detection of viral nucleic acid by PCR in throat, saliva, or urine specimens should be considered in clinically compatible situations.

Positive: presence of IgM-class antibodies to mumps virus may support a clinical diagnosis of recent/acute phase infection with this virus.

Negative: absence of IgM-class antibodies to mumps virus suggests lack of acute phase infection with mumps virus. However, serology may be negative in early disease, and results should be interpreted in the context of clinical findings.

Results must always be interpreted together with other clinical and laboratory findings.

Serum specimens drawn during the acute phase of infection may be negative by serological tests.

All positive results must be interpreted with care, as some false-positive results or heterotypical responses of the IgM have been seen in the serum of pregnant women or in patients with an acute infection caused by cytomegalovirus, herpes simplex virus, measles, rubella, and parvovirus.

Supportive Data

SeraQuest mumps IgM test kit showed a sensitivity of 97.3% and a specificity of 96.6% when 160 specimens were tested in parallel with a reference method.(Package insert: SeraQuest, 1938 NE 148th Terrace, North Miami FL)